UDEC modelling on wave propagation across fractured rock masses

Wave attenuation across fractured rock masses is a great concern of rock engineers to assess the safety of underground structures in and on rocks under dynamic loads. Due to the discreteness of rock masses, the universal distinct element code (UDEC) has been adopted for the study of rock mass problems. In this paper, the calibration work of UDEC modelling on P-wave propagation across single linearly and nonlinearly deformable fractures is conducted. Subsequently, numerical studies of P-wave propagation across multiple nonlinearly deformable fractures are carried out. The magnitude of transmission coefficient is calculated as a function of nondimensional fracture spacing for different numbers of fractures. The results reveals that under some circumstances, the magnitude of transmission coefficient not only increases with increasing number of fractures, but also is larger than 1.